The Experts below are selected from a list of 225 Experts worldwide ranked by ideXlab platform
Richard Escadafal - One of the best experts on this subject based on the ideXlab platform.
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Relationships between satellite-based radiometric indices simulated using laboratory reflectance data and typic soil color of an arid environment
Remote Sensing of Environment, 1998Co-Authors: Renaud Mathieu, Marcel Pouget, Bernard Cervelle, Richard EscadafalAbstract:By definition, the color of an object such a soil is highly dependent on its reflectance properties in the visible spectrum. In this study, the relationships between soil color and simulated reflectance values for the Landsat TM and SPOT HRV satellites are examined from a laboratory standpoint. Visible reflectance spectra were acquired for 124 soil samples originated from an arid environment, and selected radiometric indices were worked out for both sensors. All the earlier studies relative to soil color and remote sensing have considered the widely known Munsell method as a reference for soil color quantification. Some characteristics of this System based on a visual comparison of a soil sample with painted color chips may complicate the establishment of simple relationships between reflectance data and soil color. We have applied the CIE 1931 standard method of color measurement which consists in computing color parameters directly from reflectance spectra using colorimetric equations. Color data are expressed according to two polar coordinates called Helmholtz coordinates (dominant wavelength and purity of excitation) and luminance variable having a similar meaning to the Munsell hue, chroma, and value, respectively. The Munsell System is also employed to estimate soil color. Linear regression analysis between soil color and radiometric indices show a Systematic improvement of correlations (r) from about 0.7 to more than 0.9 using Munsell data and Helmoltz data, respectively. Simple radiometric indices (band combinations) calculated from broad blue, green, and red bands are found to be good predictors of each of the soil color components. The increasing availability of spectroradiometers', including in the field, should stimulate the use of Helmholtz coordinates, as a beneficial alternative to the Munsell chart to obtain a precise and reproducible color quantification which may be useful for remote sensing applications. The radiometric indices utilized in this study are potentially helpful to contribute to soil resource and soil degradation cartography using visible satellite data in vast arid regions where soil data are not readily available.
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Relationships between satellite-based radiometric indices simulated using laboratory reflectance data and typic soil color of an arid environment
Remote Sensing of Environment, 1998Co-Authors: Renaud Mathieu, Marcel Pouget, Bernard Cervelle, Richard EscadafalAbstract:By definition, the color of an object such a soil is highly dependent on its reflectance properties in the visible spectrum. In this study, the relationships between soil color and simulated reflectance values for the Landsat TM and SPOT HRV satellites are examined from a laboratory standpoint. Visible reflectance spectra were acquired for 124 soil samples originated from an arid environment, and selected radiometric indices were worked out for both sensors. All the earlier studies relative to soil color and remote sensing have considered the widely known Munsell method as a reference for soil color quantification. Some characteristics of this System based on a visual comparison of a soil sample with painted color chips may complicate the establishment of simple relationships be between reflectance data and soil color. We have applied the CIE 1931 standard method of color measurement which consists in computing color parameters directly from reflectance spectra using colorimetric equations. Color data are expressed according to two polar coordinates called Helmholtz coordinates (dominant wavelength and purity of excitation) and a luminance variable having a similar meaning to the Munsell hue, chroma, and value, respec tively. The Munsell System is also employed to estimate soil color. Linens regression analysis between soil color and radiometric indices show a Systematic improvement of correlations (r) from about 0.7 to more than 0.9 using Munsell data and Helmoltz data, respectively. Simple radiometric indices (band combinations) calculated from broad blue, green, and red bands are found to be good predictors of each of the soil color components. The increasing availability of spectroradiometers, including in the field, should stimulate the use of Helmholtz coordinates, as a beneficial alternative to the Munsell chart to obtain a precise and reproducible color quantification which may be useful for remote sensing applications. The radiometric indices utilized in this study are potentially helpful to contribute to soil resource and soil degradation cartography using visible satellite data in vast arid regions where soil data are not readily available. (C)Elsevier Science Inc., 1998.
Renaud Mathieu - One of the best experts on this subject based on the ideXlab platform.
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Relationships between satellite-based radiometric indices simulated using laboratory reflectance data and typic soil color of an arid environment
Remote Sensing of Environment, 1998Co-Authors: Renaud Mathieu, Marcel Pouget, Bernard Cervelle, Richard EscadafalAbstract:By definition, the color of an object such a soil is highly dependent on its reflectance properties in the visible spectrum. In this study, the relationships between soil color and simulated reflectance values for the Landsat TM and SPOT HRV satellites are examined from a laboratory standpoint. Visible reflectance spectra were acquired for 124 soil samples originated from an arid environment, and selected radiometric indices were worked out for both sensors. All the earlier studies relative to soil color and remote sensing have considered the widely known Munsell method as a reference for soil color quantification. Some characteristics of this System based on a visual comparison of a soil sample with painted color chips may complicate the establishment of simple relationships between reflectance data and soil color. We have applied the CIE 1931 standard method of color measurement which consists in computing color parameters directly from reflectance spectra using colorimetric equations. Color data are expressed according to two polar coordinates called Helmholtz coordinates (dominant wavelength and purity of excitation) and luminance variable having a similar meaning to the Munsell hue, chroma, and value, respectively. The Munsell System is also employed to estimate soil color. Linear regression analysis between soil color and radiometric indices show a Systematic improvement of correlations (r) from about 0.7 to more than 0.9 using Munsell data and Helmoltz data, respectively. Simple radiometric indices (band combinations) calculated from broad blue, green, and red bands are found to be good predictors of each of the soil color components. The increasing availability of spectroradiometers', including in the field, should stimulate the use of Helmholtz coordinates, as a beneficial alternative to the Munsell chart to obtain a precise and reproducible color quantification which may be useful for remote sensing applications. The radiometric indices utilized in this study are potentially helpful to contribute to soil resource and soil degradation cartography using visible satellite data in vast arid regions where soil data are not readily available.
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Relationships between satellite-based radiometric indices simulated using laboratory reflectance data and typic soil color of an arid environment
Remote Sensing of Environment, 1998Co-Authors: Renaud Mathieu, Marcel Pouget, Bernard Cervelle, Richard EscadafalAbstract:By definition, the color of an object such a soil is highly dependent on its reflectance properties in the visible spectrum. In this study, the relationships between soil color and simulated reflectance values for the Landsat TM and SPOT HRV satellites are examined from a laboratory standpoint. Visible reflectance spectra were acquired for 124 soil samples originated from an arid environment, and selected radiometric indices were worked out for both sensors. All the earlier studies relative to soil color and remote sensing have considered the widely known Munsell method as a reference for soil color quantification. Some characteristics of this System based on a visual comparison of a soil sample with painted color chips may complicate the establishment of simple relationships be between reflectance data and soil color. We have applied the CIE 1931 standard method of color measurement which consists in computing color parameters directly from reflectance spectra using colorimetric equations. Color data are expressed according to two polar coordinates called Helmholtz coordinates (dominant wavelength and purity of excitation) and a luminance variable having a similar meaning to the Munsell hue, chroma, and value, respec tively. The Munsell System is also employed to estimate soil color. Linens regression analysis between soil color and radiometric indices show a Systematic improvement of correlations (r) from about 0.7 to more than 0.9 using Munsell data and Helmoltz data, respectively. Simple radiometric indices (band combinations) calculated from broad blue, green, and red bands are found to be good predictors of each of the soil color components. The increasing availability of spectroradiometers, including in the field, should stimulate the use of Helmholtz coordinates, as a beneficial alternative to the Munsell chart to obtain a precise and reproducible color quantification which may be useful for remote sensing applications. The radiometric indices utilized in this study are potentially helpful to contribute to soil resource and soil degradation cartography using visible satellite data in vast arid regions where soil data are not readily available. (C)Elsevier Science Inc., 1998.
Marcel Pouget - One of the best experts on this subject based on the ideXlab platform.
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Relationships between satellite-based radiometric indices simulated using laboratory reflectance data and typic soil color of an arid environment
Remote Sensing of Environment, 1998Co-Authors: Renaud Mathieu, Marcel Pouget, Bernard Cervelle, Richard EscadafalAbstract:By definition, the color of an object such a soil is highly dependent on its reflectance properties in the visible spectrum. In this study, the relationships between soil color and simulated reflectance values for the Landsat TM and SPOT HRV satellites are examined from a laboratory standpoint. Visible reflectance spectra were acquired for 124 soil samples originated from an arid environment, and selected radiometric indices were worked out for both sensors. All the earlier studies relative to soil color and remote sensing have considered the widely known Munsell method as a reference for soil color quantification. Some characteristics of this System based on a visual comparison of a soil sample with painted color chips may complicate the establishment of simple relationships between reflectance data and soil color. We have applied the CIE 1931 standard method of color measurement which consists in computing color parameters directly from reflectance spectra using colorimetric equations. Color data are expressed according to two polar coordinates called Helmholtz coordinates (dominant wavelength and purity of excitation) and luminance variable having a similar meaning to the Munsell hue, chroma, and value, respectively. The Munsell System is also employed to estimate soil color. Linear regression analysis between soil color and radiometric indices show a Systematic improvement of correlations (r) from about 0.7 to more than 0.9 using Munsell data and Helmoltz data, respectively. Simple radiometric indices (band combinations) calculated from broad blue, green, and red bands are found to be good predictors of each of the soil color components. The increasing availability of spectroradiometers', including in the field, should stimulate the use of Helmholtz coordinates, as a beneficial alternative to the Munsell chart to obtain a precise and reproducible color quantification which may be useful for remote sensing applications. The radiometric indices utilized in this study are potentially helpful to contribute to soil resource and soil degradation cartography using visible satellite data in vast arid regions where soil data are not readily available.
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Relationships between satellite-based radiometric indices simulated using laboratory reflectance data and typic soil color of an arid environment
Remote Sensing of Environment, 1998Co-Authors: Renaud Mathieu, Marcel Pouget, Bernard Cervelle, Richard EscadafalAbstract:By definition, the color of an object such a soil is highly dependent on its reflectance properties in the visible spectrum. In this study, the relationships between soil color and simulated reflectance values for the Landsat TM and SPOT HRV satellites are examined from a laboratory standpoint. Visible reflectance spectra were acquired for 124 soil samples originated from an arid environment, and selected radiometric indices were worked out for both sensors. All the earlier studies relative to soil color and remote sensing have considered the widely known Munsell method as a reference for soil color quantification. Some characteristics of this System based on a visual comparison of a soil sample with painted color chips may complicate the establishment of simple relationships be between reflectance data and soil color. We have applied the CIE 1931 standard method of color measurement which consists in computing color parameters directly from reflectance spectra using colorimetric equations. Color data are expressed according to two polar coordinates called Helmholtz coordinates (dominant wavelength and purity of excitation) and a luminance variable having a similar meaning to the Munsell hue, chroma, and value, respec tively. The Munsell System is also employed to estimate soil color. Linens regression analysis between soil color and radiometric indices show a Systematic improvement of correlations (r) from about 0.7 to more than 0.9 using Munsell data and Helmoltz data, respectively. Simple radiometric indices (band combinations) calculated from broad blue, green, and red bands are found to be good predictors of each of the soil color components. The increasing availability of spectroradiometers, including in the field, should stimulate the use of Helmholtz coordinates, as a beneficial alternative to the Munsell chart to obtain a precise and reproducible color quantification which may be useful for remote sensing applications. The radiometric indices utilized in this study are potentially helpful to contribute to soil resource and soil degradation cartography using visible satellite data in vast arid regions where soil data are not readily available. (C)Elsevier Science Inc., 1998.
Bernard Cervelle - One of the best experts on this subject based on the ideXlab platform.
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Relationships between satellite-based radiometric indices simulated using laboratory reflectance data and typic soil color of an arid environment
Remote Sensing of Environment, 1998Co-Authors: Renaud Mathieu, Marcel Pouget, Bernard Cervelle, Richard EscadafalAbstract:By definition, the color of an object such a soil is highly dependent on its reflectance properties in the visible spectrum. In this study, the relationships between soil color and simulated reflectance values for the Landsat TM and SPOT HRV satellites are examined from a laboratory standpoint. Visible reflectance spectra were acquired for 124 soil samples originated from an arid environment, and selected radiometric indices were worked out for both sensors. All the earlier studies relative to soil color and remote sensing have considered the widely known Munsell method as a reference for soil color quantification. Some characteristics of this System based on a visual comparison of a soil sample with painted color chips may complicate the establishment of simple relationships between reflectance data and soil color. We have applied the CIE 1931 standard method of color measurement which consists in computing color parameters directly from reflectance spectra using colorimetric equations. Color data are expressed according to two polar coordinates called Helmholtz coordinates (dominant wavelength and purity of excitation) and luminance variable having a similar meaning to the Munsell hue, chroma, and value, respectively. The Munsell System is also employed to estimate soil color. Linear regression analysis between soil color and radiometric indices show a Systematic improvement of correlations (r) from about 0.7 to more than 0.9 using Munsell data and Helmoltz data, respectively. Simple radiometric indices (band combinations) calculated from broad blue, green, and red bands are found to be good predictors of each of the soil color components. The increasing availability of spectroradiometers', including in the field, should stimulate the use of Helmholtz coordinates, as a beneficial alternative to the Munsell chart to obtain a precise and reproducible color quantification which may be useful for remote sensing applications. The radiometric indices utilized in this study are potentially helpful to contribute to soil resource and soil degradation cartography using visible satellite data in vast arid regions where soil data are not readily available.
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Relationships between satellite-based radiometric indices simulated using laboratory reflectance data and typic soil color of an arid environment
Remote Sensing of Environment, 1998Co-Authors: Renaud Mathieu, Marcel Pouget, Bernard Cervelle, Richard EscadafalAbstract:By definition, the color of an object such a soil is highly dependent on its reflectance properties in the visible spectrum. In this study, the relationships between soil color and simulated reflectance values for the Landsat TM and SPOT HRV satellites are examined from a laboratory standpoint. Visible reflectance spectra were acquired for 124 soil samples originated from an arid environment, and selected radiometric indices were worked out for both sensors. All the earlier studies relative to soil color and remote sensing have considered the widely known Munsell method as a reference for soil color quantification. Some characteristics of this System based on a visual comparison of a soil sample with painted color chips may complicate the establishment of simple relationships be between reflectance data and soil color. We have applied the CIE 1931 standard method of color measurement which consists in computing color parameters directly from reflectance spectra using colorimetric equations. Color data are expressed according to two polar coordinates called Helmholtz coordinates (dominant wavelength and purity of excitation) and a luminance variable having a similar meaning to the Munsell hue, chroma, and value, respec tively. The Munsell System is also employed to estimate soil color. Linens regression analysis between soil color and radiometric indices show a Systematic improvement of correlations (r) from about 0.7 to more than 0.9 using Munsell data and Helmoltz data, respectively. Simple radiometric indices (band combinations) calculated from broad blue, green, and red bands are found to be good predictors of each of the soil color components. The increasing availability of spectroradiometers, including in the field, should stimulate the use of Helmholtz coordinates, as a beneficial alternative to the Munsell chart to obtain a precise and reproducible color quantification which may be useful for remote sensing applications. The radiometric indices utilized in this study are potentially helpful to contribute to soil resource and soil degradation cartography using visible satellite data in vast arid regions where soil data are not readily available. (C)Elsevier Science Inc., 1998.
Vanessa A Hammond - One of the best experts on this subject based on the ideXlab platform.
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Research Article Validity and Reliability of the Munsell Soil Color Charts for Assessing Human Skin Color
2016Co-Authors: Anthony I. Reeder, Ella Iosua, Andrew R. Gray, Vanessa A HammondAbstract:Background: Skin pigmentation is a key factor for ultraviolet radiation exposure–related cancers and can make a significant contribution to the patterns of other diseases. For surveys, and to appropriately target cancer control activities, valid and reliable measures of skin color are required. Methods: Validity and reliability of the Munsell Soil Color Charts were investigated for skin color assessment. The unexposed skin color of 280 university students was measured by spectrophotometer to calculate an Individual Typology Angle (ITA) value, and categorized by two independent raters according to the Munsell System (the latter was repeated after a 7-day interval). Results: Interrater and intrarater reliability for the Munsell charts was found to be acceptable [intraclass correlation coefficients (ICC) of 0.85 and0.86, respectively].When ITAvalueswere converted to the sixDelBino skin color categories, weighted k for agreement between raters, within rater, and between Munsell chip and spectrophotometerwere 0.63, 0.60, and0.61, respectively. A tendency towardoverestimation of the extremes of skin pigmentation was evident, particularly for the "brown " and "dark " skin types. Conclusions: Study findings suggest that the Munsell Soil Color Charts represent a reliable and valid measurement strategy when assessing skin type. Impact: The Munsell Year 2000 Soil Color Charts may provide a useful instrument for fieldwork contexts. Subsequent classification of individuals into skin cancer risk categories, rather than the use of precise ITA values,may be sufficient for targeting public healthmessages for skin cancer prevention and other health risks. Cancer Epidemiol Biomarkers Prev; 1–7. 2014 AACR
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validity and reliability of the Munsell soil color charts for assessing human skin color
Cancer Epidemiology Biomarkers & Prevention, 2014Co-Authors: Anthony I. Reeder, Ella Iosua, Andrew R. Gray, Vanessa A HammondAbstract:Background: Skin pigmentation is a key factor for ultraviolet radiation exposure–related cancers and can make a significant contribution to the patterns of other diseases. For surveys, and to appropriately target cancer control activities, valid and reliable measures of skin color are required. Methods: Validity and reliability of the Munsell Soil Color Charts were investigated for skin color assessment. The unexposed skin color of 280 university students was measured by spectrophotometer to calculate an Individual Typology Angle (ITA) value, and categorized by two independent raters according to the Munsell System (the latter was repeated after a 7-day interval). Results: Interrater and intrarater reliability for the Munsell charts was found to be acceptable [intraclass correlation coefficients (ICC) of 0.85 and 0.86, respectively]. When ITA values were converted to the six Del Bino skin color categories, weighted κ for agreement between raters, within rater, and between Munsell chip and spectrophotometer were 0.63, 0.60, and 0.61, respectively. A tendency toward overestimation of the extremes of skin pigmentation was evident, particularly for the “brown” and “dark” skin types. Conclusions: Study findings suggest that the Munsell Soil Color Charts represent a reliable and valid measurement strategy when assessing skin type. Impact: The Munsell Year 2000 Soil Color Charts may provide a useful instrument for fieldwork contexts. Subsequent classification of individuals into skin cancer risk categories, rather than the use of precise ITA values, may be sufficient for targeting public health messages for skin cancer prevention and other health risks. Cancer Epidemiol Biomarkers Prev; 23(10); 2041–7. ©2014 AACR .
